DESCRIPTION: Respiratory protection represents the last resort for protection against harmful contaminants. However, in their daily work activity a large number of workers rely on respirators for their protection. In the case of gas phase contaminants, cartridges containing adsorbing material are used to remove the gases and vapors from the breathing zone. Pure or impregnated Granular Activated Carbon (GAC) is the main adsorbent used in respirators for a large number of vapors and gases which may exist in the workplace. A number of drawbacks including low capacity, low selectivity and the requirement of expensive and sometime difficult to wear cartridges as containment, makes GAC a less than ideal adsorbent. Activated Carbon Fibers (ACF) present a number of advantages over GAC including better adsorption capacity and faster kinetics, but they are much more expensive than GAC and have not been considered a viable alternative. The development of a new ACF family using inexpensive glass fibers as a substrate for carbonized phenolic resin makes ACF more competitive. The new microporous composite materials, Fibrous Porous Materials (FPMs) have shown improved adsorption performance over GAC in the adsorption of a number of compounds. However their use in respiratory protection has not yet been explored. The research proposed here aims to investigate the properties of the FPMs relevant to their use in respiratory protection against gas phase contaminants. This research will bring a better understanding of the ACF adsorption process in general and the applicability of these materials for respiratory protection by investigating: 1. The adsorption characteristics of FPMs for a number of gases, vapors and mixtures under dynamic conditions, 2. The applicability of relevant adsorption models to predict the adsorption efficiency and service life of respiratory devices using FPMs, 3. The effect of fiber orientation and packing density on the pressure drop and adsorption efficiency of cartridges using FPMs.